Home Nations is a term to refer to the four constituent parts of the United Kingdom - England, Scotland, Wales and Northern Ireland - collectively, but as separate entities, distinct from the United Kingdom as a whole. Its usage is rare (especially outside the UK), though it is more common in sporting contexts.

Sometimes the term is used to include all the self-governing nations or states of the British Isles (thus including the Republic of Ireland, the Isle of Man and the Channel Islands). Ireland can refer to the official name of the Republic of Ireland, or the whole island of Ireland (the latter usage is incorrect in a list of states or jurisdictions in the British Isles, while the former usage is ambiguous).

The term is often used when referring to sporting events in which each Home Nation competes separately, such as the now defunct British Home Championship in football. Rugby union is often cited as an exception as the Ireland team represents both Northern Ireland and the Republic of Ireland, yet Ireland is usually represented by a united team in most sports(soccer being a rare exception). In this context, it is common for all of Ireland to be referred to as a Home Nation.

The description of Northern Ireland as a nation is controversial and perhaps inaccurate. It is that part of Ireland which remained within the United Kingdom after 1922. Ireland can be and is still considered a single nation despite the two jurisdictions, with the most obvious effect being a single national rugby union team. Referring to the island of Ireland as a single country is usually incorrect through ambiguity - "country" is usually used in place of "independent state" as well as "nation".